Process of producing metal substances



PATENT 7 OFFICE. Y

nanny newsman, or nnenwoon, PENNSYLVANIA.

rnocnss or rnonucme METAL SUBSTANCES.

No Drawing.

Toallwkomitmyco ncem:

Be it known that I, HENRY 0.; P. WEBER a resident of Edgewood, in the county of Allegheny and State of Pennsylvama, have invented anew and useful Improvement 1n Processes of .Producing Metal- Substances, of which the following is. a specification.

The invention relates to a process of producing metals which are reducible only with difiiculty bythe ordinary methods.

Metals which are readily reducible from their ores or. compounds are ordinarily produced by heating an easily. available ore or compound of the metal either alone or .with

the-addition of well known reducing agents, such. forinstance as-carbon. The reduction of iron from its ores or compounds isa well knownexample. Certain metal ores or compounds however,-do not lendthemselves to this simple treatment, and heretofore have been reduced only with difficulty-or ve mcompletely; Thisis the case particu arly with, suchv metals as chromium, tungsten,

molybdenum, uranium, titanium, columbium,tantalum, zirconium, cerium, thorium,- -vanadium, beryhum, and others. Such metals are ordinarily produced by treating a suitable compound thereof 1n a fused state, at very, high temperatures, with more powerful reducm agents, butthis method is expensive am? not veg tion'is the so-called umino-thermic process in which metallic aluminum in a fine state is used as the reducing agent, acting upon the metallic compound in a state of either fusion or of incipient fusion, wherein the necessary temperature is furnished by the heat of the exothermic reaction. This, as well as the other process mentioned above, depends upon the fact that the heatof formatlon of the compound to be reduced is less than that of the compounds formed in the reduction.

Attempts have "also been made to produce these metals by electrochemical methods,

either at ordinary temperatures or in fused eflicient. .An ex'cep- 1 I," Specincation'of Letters Patent. Patented Mar. 29, 1921. application filed March a1, 1919. Serial No. I

difliculties rapidly increase asthe metals to v be reduced become more electrochemical reduction of such metals, such forinstance as chromium, has not been successfully practised so far.

refractory. The

The improvedprocess differs .fundamcntally from anyof the prior methods in that it does not depend upon a reaction between a liquid (fused solid)'and a solid, or ibetween two liquids (fused solids); nor does it depend essentially upon the heats of formation of the substancesorcompounds par- I ticipatin in the reaction; nor upon the position of t e metals concerned in'theelectrochemical series. Thus, for instance,$I can reduce "chromium'compounds by less electro positive metals, such as'copper or gold.

. The reaction upon which the new process depends is between 'af'vapor whichyis a compound of the metal to be other metal which may be eithersolid or in a fused condition and which is itself capable of being converted into a volatile compound during the process. The availability of this process for reducing any metal substance or origlnally present and those formed during the reaction, and their relative quantities, which may be controlled.

The process can well be illustrated for the 3 production. of chromium from its ores or compounds. An anhydrous volatile compound, such as chromium chlorid, is mixed reduced, and ancompound therefore depends mostly upon with another; metal, '"such for instance ;as

iron, capable of forming a volatile compound wlth the chromium by substitution. The mixture is placed in a container which can be'evacuated and heated. The reaction sets in slowly even below red heat, and may be varied in speed and intensity by raising or lowering the temperature. 700 to 1200 centigrade is a very satisfactory range of temperature. After atime (depending upon the temperatureused) the chromium chlorid is reduced to metallic chromium,a correspondingamount of iron having been converted -into a 'volatile form, to-wi't, iron chlorid. Therefore at a moderate temperature there occurs a replacement,the vola-' tile'chr'omium chlorid giving its, chlorin to the reducing.metal, to-wit, iron. .The re-' duced in the electrochemical series, but de-' pends upon the interaction between a vaporiz'ed compound of the metal to be reduced or produced with another metallic" body which is also capable of forming a volatile compound durin' the reaction. other words, the driving orce oftheprocess depends upon the different volatilities and the relative amounts, 2'. e., concentration of the gaseous compounds, namely that originally present and the one which is formed as a result of the reaction. p

The process is general and may be used for the production of any of the metals or metalloids heretofore enumerated, or even of other metalloids, such as silicon, as well as for the, production of more easily remetalto be'reduced or or -metallic substance.

ducible metals, 'such as cobalt, nickel and iron.

The reducing agent need can be any metallic substance capable of also forming a, volatile compound during the reaction, such for instance as tin, zmc, lead or the like. Instead of the chlorid of the roduced I may use other halogens, such as t e fiuorids, bromids, iodids, cyanids, or carbonyls, or in fact-any form of vaporized compound which during the reaction will give up its volatile' constituent to combine with the reducing metal By varying the conditions a wide variety of results can be obtained. Thus if the reducing metal (for instance iron) is added as a fine powder the reaction takesplace rapidly and at lower temperatures, and the product (for instance chromium) is in powdered or granular form. If on the other hand solid pieces of reducing metal are used and the reaction is effected below the melting point of the metals, the reduced metal (for instance chromium) is deposited upon the reducin metal (for instance iron) as a coating. If an excess of the reducin metal is used and the temperature is eld high enough, an alloy results (an alloy of iron and chromium under theconditions assumed) Furthermore, by simultaneously reducing the volatile compounds of two or more metals, an alloy can be produced. Thus if the c'hlorids of chromium and of nickel are simultaneously treated with the reducing metal in the form of a powder and at a low temperature, the resulting material will be a mixture of' granulated or powdered chromium and nickel, which can be melted to form a nickel-chromium alloy; or if the chlorid of chromium and nickel be treated with an excess of iron and the temperature not be iron, but

maintained high, it will result in a nickel-.

chromium-iron allo Likewise if two or more reducing meta s'are used in excess, and the temperature maintained high, a triple alloy will also result, such for instance as reducing chlorid of chromium by the use of both ironand nickel in excess and at a high temperature, in which '='case a. chromiumnickel-iron alloy is formed. r

The process therefore is adapted not merely for producing diflicultly reducible metals in' ,ure form, but also for producing various al oys thereof with metals which are capable of acting as reducing metals in the process; and also for depositing a coating of the diflicultl reducible metals on the surfaces of soli bodies of the reducing metals. For best securin the latter result the iron, steel or other sohd metal which is to be coated is first cleaned and dried and then placed in a" receptacle which evacuated, is covered wit a layer of anhydrous chromium chlorid, the receptacle then evacuated and gradually heated, whereupon by the decomposition described, ferric chlor1d is driven off and the chromium is deposited on the iron or steel body. The depth ate of the coating can be regu d by .the temperature and by the length of time that the reaction is allowed to proceed.v

It is not essential to the rocess that the volatile substances from-"whlch the metal is to be produced or deposited are present originally. Thus, the volatile compound (such as chromium chlorid) may be formed agent (for. instance'iron) may be formed at another stage of the process,the essential features of the process consisting in the presence of the reducible volatile compolmd (for instance chromium chlorid) at onestage of the process, and the subsequent reduction of the metal to metallic form from the volatile compound by another substance (for instance iron), whether these components are originally present or are roduced during the course of the reaction. iior instance, for the production of chromium, the commercial process would start with chromic oxid (or possibly chromite) which would be convert ed into the chlorid by means of carbon and 'chlorin in conjunction with each other according to the well known method, and this lproduct would without further purification referably can be at one stage of the process, and the reducing know-n reducin agent, again converted into metallic iron. he regenerated 1ron then re-' duces a fresh portion of the volatile chromium compound. In the samewaythechloring driven off in'reducing the ferric chlorid to I'do not wish to limit myself to the use of a vacuum as described. One purpose of the vacuum is to hasten the reaction. This however can be effected by the use of catalyzers (fine powdersg such as are commonly employed to acce to revent access of interfering substances, suc as water vapor, oxygen and the like during the reaction. This result however can be obtained b carrying on the process in an inert atmosp ere, such as nitrogen. It is however desirable to carry out the process in the absence of oxygen or substances capable of yielding oxygen.

I claim:

1. The process of producing metals and metalloids of the character described, which consists in forming a sublimable compound of the metal substance to be'redu'ced, and reducing such compound by another metallic substance capable of also forming a volatile compound during the reaction.

2. The process of producing metals and metalloids of the character described, which consists in forming a sublimable compound of the metal substance to be reduced, and heating the same in contact with a metalllc substance capable of also forming a volatile compound and thereby reducing the metal of the first named vapor compound.

3. The process of producing metals and metalloids of the character described, which consists in forming a volatile compound of the metal substance to be reduced, reducing said compound by another metallic substance capable of also forming a volatile compound during the reaction, and during such reaction excluding interfering substances, such as oxygen and substances capable of yielding oxygen.

4.. The process of producing metals and metalloids of the character described, whlch consists in forming a volatile compound of the metal substance to be reduced, reducing said compound by another metallic sub stance capable of -also forming a volatile compound. during the reaction, and adding a catalyzer to hasten the reaction.

' 5. The process of producing metals and metalloids of the character described, which erate gas reactions. Another. purpose of the employment of a vacuum is.

9.' The process consists' in forming a volatile compound of the metal substance to be reduced, and reducing said compound by another metallic substance in a finely divided state'a'nd' capable of also formingpa volatile compound during, the reaction, said reduction being carried on at a temperature below the melting pointof the metal to be produced.

The process of producingv allo s from metals and metalloid substances of t e character described, which consists in forming volatile com ounds of several metallic substances of tlib character described, and reducing said compounds by another metallic substance capable of also forming a volatile compound during the reaction.

7. The process of producing alloys from metals and metalloid substances of the'character described, which consists in forming a volatile compound of a metal substance of the character described and reducin the said compound byan alloy capable 0 also forming a volatlle compound during the 7 reaction.

8. The process of forming alloys from:

metals and metalloid substances of the character described, which consists in forming a volatile compound of a metal substance of thecharacter described, and reducing said compound by an excess of another metallic substance capable of also forming a vola-' tile compound during the reaction.

7 of producing metals and metalloids of the character described, which consists in reducin the metal to be reduced by a substance capable of lYielding during the process .a metal or meta oid and which is ca able of also forming a volatile compound diiring the reaction, said substance being heated to a temperature below its melting point.

10. The process of producing metals and metalloids which consists in forming a volatile compound of the metal to be produced,

mixing the same with a metal capable of forming a volatile compound during the reaction and heating the mixture.

11. The process of producing metals and metalloids which conslsts in forming a volatile compound of the metal to be produced, mixing the same with a metal capable of forming a volatile compound during the reaction, placin the mixture under vacuum and heating t e same.

12. The process of producing metals and metalloids which consists in forming a volatile compound of the metal to be produced, mixing the same with a metal capable of forming a volatile compound during the reaction and heating .the mixture, the compound of said second metal being more volatile than the compound of said first metal.

13. The process of producing metals and metalloids which consists in forming a volaa volatile compound of tile halid of-the metal to be produced, mix ing thesame with a metal capable of form-' ing a volatile halid during the reaction and heating the mixture, the halid'of the second metal being more volatile than the halid of said first metal.

14. The process of producing chromium which conslsts informing chromium chlo- HENRY c. P. WEBER.

Witness: Amen A. TRILL. 

